1. Field of the Invention
The present invention relates to a wireless tag determination system and a wireless tag determination method for determining reliability of existence of an object, to which a wireless tag is attached, within a detection range of a tag reader.
2. Description of the Related Art
Methods of finding reliability of measurement data by use of an update interval of a sensor have heretofore been proposed.
For example, the following system has been disclosed (see, for instance, Fujinami, Kaori, and Tatsuo Nakajima, “Framework for Constructing a Context-aware Application under Ubiquitous Environment,” Proceedings of Computer System Symposium, pp. 91-98, 2002). In this system, the inverse number of an update interval of a sensor is defined as an index (a time precision) that represents the degree of reproducibility of measurement data. Thus, by regarding a higher time precision as the higher reproducibility of measurement data, the system determines that it is highly likely to obtain the same measurement data at the next time of polling the sensor.
Meanwhile, there is also disclosed a system for allowing reliability of point-of-interest (POI) data to be grasped by displaying information on the reliability of the POI data (see, for instance, Japanese Patent Application Laid-open No. 2004-286653).
However, the above-described method using the time precision as the index is focused only on the update interval of the sensor. For this reason, the reliability of measurement data cannot be obtained in a case, for example, where a tag reader cannot detect a wireless tag because of a surrounding radio wave environment even though the wireless tag exists within a detection range of the tag reader.
The reliability of the POI data needs to be set up for each piece of the POI data by a creator of a database or the like. It is difficult to set up the reliability for each of the large amount of pieces of POI data. In addition, reliability may vary because the reliability is determined from a subjective point of view of the creator of the database or the like, who sets up the POI data.